Motion-transmitting mechanism



May 16, 1944.

B. BRAss LL 2,349,135

MOTION TRANSMITTING MECHANISM Filed July 16, 1941 4 Sheets-Sheet 1 Bryanflraasell B. BRASSELL MOTION TRANSMITTING MECHANISM May 16, 1944.

4 Sheets-Sheet 2 Filed July 16, 1941 Bryan flmasell B. BRASSELL MOTIONTRANSMITTING MECHANISM May 16, 1944 4 Sheets-Sheet 3 Filed July 16, 1941flrgan fir assell ay 16, 19. B. BRASSELL 2,349,135

MOTION TRANSMITTING MECHANISM Filed July 16, 1941 4 Sheets-Sheet 4Patented May 16, 1944 UNITED STATES PATENT OFFICE 2,349,135MOTION-TRANSMITTING MECHANISM Bryan Brassell, Puerto de Luna, N. Mex.Application July 16, 1941, Serial No. 402,652

14 Claims. (01. 3-205) This invention relates to improvements inmotion-transmitting mechanisms, and relates more particularly tomechanisms involving the driving of a reciprocating driven member and,more specifically, where the driven member is itself being driven by areciprocatory drive member.

The reciprocation of a driven member from a power source necessarilyinvolves a number of problems, including those of length of stroke,speed, etc., but one of the major diiiiculties arises through theconditions presented in the end zones of reciprocation. In such zonesthe member must approach the extreme, come to a stop, and then begintravel in the opposite direction. Obviously, the greater the speed, thegreater becomes the problem conditions, since the member ends its strokeat the same point regardless of speed, the latter determining therapidity of approach and the rapidity with which the beginning of thesucceeding stroke must take place.

The conditions can be readily understood by considering the drivenmember as the pump rod or actuator of a pumping system; with the rodmoving vertically; assuming the system operating to pump in onedirection, the approach to the lower extreme is made without load, thecondition changing when the rod reaches its extreme position, the loadbecoming manifest at the beginning of the return stroke. The specificcharacteristics at the instant of change are those of first bringing theinertia of motion to a condition of inertia of rest and then immediatelyresuming the inertia of motion but with the latter in the oppositedirection and with the load added. The speed will determine the timewithin which these changes can take place, so that the greater the speedof member movement the less becomes the time within which the change canbe made.

After the succeeding inertia of motion has been established it isreadily continued until the opposite end zone is reached. But duringthis period of transition during which the inertia of motion must bereversed in direction-with the intervening inertia of rest essential-isto be found one of the problems which are presentthe resumption of theinertia of motion in the opposite direction (with the load added andincreasing resistance) and in which the speed can determine whether ornot the change can be made without shock.

In a companion application filed March 11, 1941, Serial No. 382,823, (U.S. Patent No. 2,273,173, issued February 1'7, 1M2) conditions such asthis are presented, with the solution of the problems involved providedby the use of a reciprocating drive member operated by a suitable powersource-preferably a rotating member connected with the drive member bysuitable connections to thereby convert the rotary motion of the powersource into reciprocatory movement of the drive member; the drive anddriven members are connected by a leverage assembly designed to set up adifierential in speed characteristic between the two members within theend zones of reciprocation of the drive member. The assembly thereforehas the speed of the drive member controlled by the speed variations setup by the power source, while the speed of the driven member-the latterdriven by the drive member through the leverage assembly with theleverage assembly partaking of the speed variations of the drivemember-is varied from that of a one-to-one relation between the members,present in the intermediate zone, to an increasing differential duringapproach in the end zones, with the result that the speed of the drivenmember is reduced within the end zones.

The difficulties within the end zone can be understood by consideringthe efiect of the travel of the power source-a crank-pin, forinstancethrough its dead center zones, such travel representing theapproach, stop and reversal of the driven member in each of its endzones of reciprocation. During the arcuate travel of the crank-pinthrough such dead center zone, the pin approaches, reaches, passes, andthen leaves a point which represents the extreme or reciprocation, withthe pin moving continuously through the arc. Obviously, therefore, theperiod of time during which the crank-pin is positioned within suchpoint is practically imperceptible, since it represents a single pointin the circumference of the circle, and the approach to and succeedingadvance from such point actually represent movements of the two strokesof the reciprocating member. Yet, if the cycle of the inertia of motion,inertia of rest, and inertia of motion in the opposite direction, is tobe established, the inertia of rest must be obtained during thisimperceptible period during which the crank-pin is passing the zenith ornadir points of its travel. Hence, the inertia of rest condition is moreor less theoretical under conditions such as this.

While the arcuate path of the crank-pin through the dead-center zonerepresents but a short portion of the length of the reciprocating mustalso pass through this cycle concurrently with the drive member. Hence,the speeds employed are designed to prevent such conditions of shock,or, if higher speeds are contemplated to cushion the shock by partialsuccess.

the attempt is made springs, etc., with but A fundamental of the presentinvention is based on the assumption that if the theoretical andimperceptible inertia of rest periods is prolonged into a dwellcharacteristic, certain of the difliculties of the end Zone willdisappear, due to the fact that the member will reach a definite end andproduce a complete rest status, and that the succeeding beginning of theinertia of motion movement in the opposite direction will take placeunder the more favorable conditions, since momentum, stretch, etc., willhave become inactive as factors opposing the change in direction ofmotion, and the beginning of the return stroke will be opposed only bythe load. The dwell is provided under conditions analogous to those of alost-motion efiect, set up by the action of the mechanism connecting thedrive and driven members, and may be of a desired length, to ensure thatthe dwell period has become complete before beginning the succeedingstroke. Since the dwell takes place while the crankpin continues itsmovement in its orbital path, the pin will have passed the zenith ornadir point of the'dead center positions at the beginning of thesucceeding stroke of the driven memher, so that the drive member willhave begun such stroke prior to the beginning of activity of the drivenmember stroke in such direction. To avoid any difiiculty as to speedunder the changed conditions, the connecting mechanism between the driveand driven members is arranged in such manner as to set up a percentagespeed relationship between the two members at the be ginning of thedriven member movement-thus providing a diiferential in speed valuecharacteristic as between the members; this differential decreases invalue as the two members advance until the differential reaches zero ata selected point in the length of the stroke, after which both memberscontinue their travel in the one to-one ratio to the end of the stroke.

The invention is preferably designed for service under double-actingpumping service conditions-conditions where each stroke of the drivenmember is a pumping stroke; under such conditions both strokes of themember are made in presence of resistance effects of general similarity,and it is possible to set up uniform operating conditions to ensure theproper operation of the assemblage.

As will be understood, the cycles of the drive and driven members varyfrom each other due to the particular arrangement. The cycle of thedrive member is determined by the movement of the power source, so thatsuch member reaches the ends of the stroke when the crank-pin is in itszenith and nadir positions, the speed of the member between these pointsfollowing the var iations set up by the movement of the crank-pinthrough its orbit. However, the cycle of the driven member is variedfrom this through the fact that its beginning is delayed, the speed atthe beginning is lower, and then increased at a greater rate than thatof the drive member until both members are brought to similar speeds,after which both travel to the end of the stroke at such one-to-onespeed relationship.

In the latter respect, the present invention differs from that of thecompanion application, in that the development of the speed difierentialduring the approach period is omitted, the

driven member reaching the end of the stroke concurrently with and atthe same speed as the drive member. This is made possible through thepresence of the dwell characteristic referred to, and which permits thedriven member to come to a complete rest before beginning the succeedingstroke. Hence, the rapidity of ad- Vance during approach can not only beincreased with safety, but can be made at a more rapid rate than isusually considered possible, especially under the conditions of thedouble-acting pumping systems. In other words, the latter system canoperate with safety at considerably higher power speeds and without thenecessity of cushioning structures, etc., thus increasing the capacityand efiiciency of such systems.

While the system is particularly adapted to pumping systems of thedouble-acting type, it is not limited in action in this respect, themechanism being such as will permit its use with single-acting pumpingsystems as well, the arrangement being such that with either type, it ispossible to operate the system under higher speeds without loss ofefliciency, or to increase efliciency at the lower speeds.

To these and other ends, therefore, the nature of which will be morefully disclosed as the invention is hereinafter particularly described,said invention consists in the improved construction and combination ofparts as more particularly described in detail hereinafter, illustratedin the accompanying drawings, and more particularly pointed out in theappended claims.

In the accompanying drawings, in which similar reference charactersindicate similar parts in each of the views- Figure 1 is a diagrammaticview showing a power source, drive, and driven members, with theelements operatively connected to produce the results indicated;

Figure 2 is a similar view, on an enlarged scale, showing thecontrolling portions of the unit which operatively connects the driveand driven members, the leverage carrier being illustrated in a numberof diiferent positions;

Figure 3 is a plan view of the the cover plate being omitted;

Figure 4 is a sectional view taken on line 4-4 of Figure 3;

Figure 5 is a central vertical sectional view;

Figures 6 and 7 are cross-sectional views taken respectively on lines6-6 and 1-1 of Figure 3;

Figure 8 is a sectional view taken on line 8-8 of Figure 5.

Figure 9 is a diagrammatic view generally similar to Figure 2 with alift pump of the single-acting type (shown diagrammatically) added; and

connecting unit,

The immediate setting for the present invention is found in theoperation of pumping systems-although the invention is itself notlimited for use in this particular field alone. This particular field ofservice presents a number of problems which have tended to restrict thecapacity of such systems, especially where the system is of thedeep-well type, and while the art has developed solutions for some ofthe problems, certain of the difficulties have remained with the resultthat the capacity of the plants has been unduly limited, since effortsto increase capacity by increase in speed have resulted in loss ofefiiciency, etc. One solution of the problems involved is presented inthe disclosure of the companion application above identified, in whichcertain characteristics have been developed with a view to meeting oneof the main difficulties that are presented-the activities within theend-zones of reciprocation of the driven member. While, in certainaspects, the present invention follows that particular arrangement, thepresent invention presents certain fundamental changes not only instructure but in theory, not only with respect to the disclosure of thecompanion application, but also from the practice that 'has beenuniversally followed.

Like the companion application, the present invention contemplates theuse of a reciprocating drive member driven from a suitable powersourcepreferably a source which translates rotary motion into the termsof the reciprocatory motion of the drive member; a driven member whichis the power source for the pumping systemit may be the pump rod itself;and a mechanism which operatively connects the drive and driven membersand is in the form of a leverage system which retains connection betweenthe two members but which is subject to angularity variations during andby movement of the members with the leverage variations definitelycontrolled to set up a predetermined regimen in the relationship betweenthe two members.

One of the advantages accruing from such arrangement is the fact thatthe drive member not only can be accurately arranged for truerectilinear motion through the fact that is of relatively short length,as conpared with the driven member, but can have its movementscontrolled by the power source without undue likelihood of causingtrouble in the end-zones of reciprocation, the stroke of reciprocationof the drive member being controlled wholly by the power source. Hence,the approach of the drive member to its extremes of reciprocation andthe succeeding stroke start in the opposite direction can take placepractically free from factors such as momentum, the travel of the powersource through its zenith and nadir zones automatically developing theslow-down action during the ap proach and the pick-up action of thesucceedin stroke without being affected by possible momentum, etc., of amoving body.

In contrast, the driven member may be of considerable or great length, acondition which not only makes it difficult to ensure accuratereciprocation, but which, because of its length, can develop variousfactors, such as stretc momentum, etc., matters which can be of extremeimportance within the end zones of reciprocation, understandable fromthe fact that the power source, when passing the Zenith and nadir pointsof its travel path, is travelling in an arcuate path and hence actuallypresents but a theoretical and imperceptible inertia of rest periodbetween the two periods of inertia of motion found in the oppositestrokes of the reciprocating member. The direction of motion mustreverse during this theoretical and imperceptible period, and theslightest lag of the driven member in making this change in directionduring such imperceptible period of rest will affect the'operation andcause difficulties and loss of efficiency. Because of this condition,the power source speed range has general limits beyond which it isunsafe to pass. Attempts have been made to meet the condition by the useof shockabsorbers and the like, but these set up other difficulties,with the result that the commercial practice has limited speeds to thesafer cones.

In the companion application above identified, the problems set up havebeen met by providing a differential in speed between the two membersduring the approach to the extreme of reciprocation-reducing the speedof advance of the driven member within this end zone so that its rate ofadvance is materially less than that of the drive member. As a result,the power speed can be increased and still retain the approach speed ofthe driven member within the safe limits, thus increasing the capacitysince the members, between the extreme zones, can travel at the higherspeeds without causing difficulty. Such increase in speed can be hadsince, in such companion structure, the differential in speed relationduring approach is necessarily present in the reverse relation at thebeginning of the succeeding stroke, so that the speed increase does nottend to set up conditions of shock, etc.

The diiierential in speed condition referred to is provided, in thecompanion application, through the mechanism of the leverage assemblywhich connects the two members, and which has constant operativeconnection between the two members, but in which the angularityconditions are variable within the end zones, with the variations suchthat the distance travelled per unit of time difiers as between the twomembers within such end zones, the difierential increasing in thedirection of the extreme and reac. lug maximum within such extremeposition; in the intermediate zone the two members travel at aone-to-one ratio, the differential developing and increasing to itsmaximum during the approach to the extreme of reciprocation. The controlof the development of the differential is through the action of controlfaces which govern the movement of the leverage carriers as. the latterare moved by the drive memher. As a result, the driven member approachesits extreme at greatly reduced speed as compared with the drive. member,so that there is less likelihood of the development of the conditionswhich can develop the shock, etc., making it possible to operate thepower source safety higher speeds. The length of stroke of the driven.member is reduced as compared with that of the drive member, but thisoffers no difficulty in connection with the installation of the system.v

Like the companion application disclosure, the present invention dealswith a generally similar problem, and utilizes a similar power sourceand drive member, with the driven member operatively connected to thedrive member through a leverage assembly. In the present invention,however, the method of solving the difiiculties has been changed, andthe sought higher-speed possibilities obtained in a different manner.

The underlying theory of the present invention rests on the fundamentalcondition that because the difiiculties come through the necessity forrequiring a complete reversal in direction of motion of the drivenmember during and within the theoretical and imperceptible period ofinertia of rest, most of the difiiculty can be overcome by providing aperceptible period of rest period at the extreme of reciprocation point,so far as the driven member is concerned, with the result that thedriven member will have completed its stroke before beginning the suc--ceeding stroke. Under such conditions, the beginning of the succeedingstroke need not overcome momentum or other lag-producing effects, andthe load can be taken up with the lowered effort. In other words, byproviding a momentary dwell at the end of the stroke of the drivenmember, any kinetic efiects which may have been present will havereached an end, and the beginning of the stroke then takes place on thebasis of the actual load rather than the load plus kinetic effects. Itis apparent that if the momentary dwell period permits completedissipation of any undesired kinetic effects, the fact that such effectsmay develop during the approach period becomes unimportant. As a result,the operating speeds of the system need not be limited to speeds such aswould not present the possibility of excess kinetic effects, but canutilize speeds producing such effects without affecting the efficiencyof operation.

The delay itself is but momentary-occupying but a few degrees of thearcuate travel of the power source-but its presence changes the drivenmember regimen from that of the drive member. For instance, assumingthat the driven member approach is in one-to-one ratio with the drivemember, the two members will approach the zenith or nadir positions ofthe crank-pin of the power source at equal speeds; but when the zenithor nadir points are reached, the drive member begins its stroke in theopposite direction as the crank-pin continues itstravel, while thesimilar stroke of the driven member is momentarily delayedassumedly thevanced a few degrees angular distance past the zenith or nadir pointduring the delay, during Which period the drive member has actuallyreversed its stroke and is beginning travel in the new direction, thuspermitting the drive member to pass through the end zone changes indirection without the presence of the driven member load at the instantof change in direction; hence the drive member can be operated safely atthe higher speed, due to its relatively short length; in addition, thedistance travelled by the drive member in such advance is small, but itis sufficient to ensure that there will be no luck on the dead centerpoint. Obviously, as the crank-pin advances, the speed of the drivemember increases, and the period of delay would therefore set up theconditions of a pick-up of the load of the driven member, a conditionthat might imply the presence of shock conditions. But the invention isdesigned to meet this condition through the leverage action and in suchmanner as to retain the efiiciency unaffected.

This is provided by affecting the speed of the driven member at theinstant of the pick-up, making it a percentage speed of that of thedrive member. For instance, the mechanism may set crank-pin will haveadup a two-to-one ratio (driven member speed as half that of the drivemember) between the members at the instant of pick-up; or it may be athree-to-one or a four-to-one ratio between the members-the particularvalue is predetermined to meet the conditions of the particularinstallation. In other words, the rate of advance of the driven memberat such time is but a percentage of that of the drive member, so thatthe drive member is not required to advance the driven member at its ownspeed at the time of impact, but at a reduced speed. After impact ishad, the difierential in speed between the mem bers is gradually reduceduntil the differential is ended, and the two members travel theremaining distance of the stroke at the one-to-one relationship. It ispossible for the control faces to be arranged to dissipate thedifferential in speed in any desired length portion of the stroke-thedissipation could extend throughout the length of the stroke, in whichcase the relative speeds of the two members would reach equality onlyduring the approach; the particular arrangement in this respect willdepend upon the particular conditions which are required to be met. Inother words, the flexibility of the invention is such that it can beadapted to meet a large variety of conditions as to installations, sincethe particular formation of the control faces can be designed to meetthe specific conditions set up by the installation.

The invention is shown diagrammatically in Figs. 1 and 2. Fig. 1indicating the general set-up, with Fig. 2 presenting an enlargedshowing of the mechanism zone, with the leverage carrier shown indifferent positions. In these views, A indicates the drive member and Bthe driven member, with the power source indicated as a rotating element0 with a link L connecting the element with the drive member to set upthe characteristics of a crank arm. With the drive member mounted fortrue reciprocation, it will be understood that the drive membermovements will conform entirely to those produced by the power source,with the member reaching its extremes of reciprocation at the zenith andnadir points of arcuate travel of the crank. The drive member A thuswill have its movements controlled wholly by the power source, and theapproach and recession speeds will be in accord with those provided bythe travel of the power source.

The driven member B is preferably in sub stantial alinement with thedrive member A, and is also mounted for reciprocation; the specificstructure of these members is presently described in greater detail, butat this point it is suiiicient to indicate that the upper end of memberB will be supported on a pin I!) which extends through a slot a ofmember A. Mounted on member A, and at opposite side zones of the latter,are a pair of arms or levers H, each lever being provided with a rollerl2 at its free end, each lever ll being also provided with a linkconnection l3 with pin Ill. The lever, roller and link connection on oneside of the drive member extend at opposite angle to those of the otherside, so that the two assemblies form what may be considered as leveragecarriers symmetrically disposed to provide a connection between thedrive and driven members.

The two leverage carriers provide a pair of swingable and articulablestructures which con-' nect the drive and driven members, each lever llbeing swingable on a pivot Ha carried by the ,uncurved, straight drivemember and individual to the lever, while the free ends of the linkconnection l3 are mounted on pin ll] of the driven member. The twoassemblies form a constant connection between the drive and drivenmembers, but, as is apparent, the articulate connection can be madeserviceable only if the leverage is definitely controlled. Such controlis the function of the control faces l4 and 15, which are designed to beoperative with the rollers l2 during opposite strokes of the members,face l4 serving as the control during the upward stroke in Fig. l, andface I5 during the downward stroke in said figure. The two faces willin. practice, he substantial duplicates, but oppositely disposedalthough this is not compulsory.

Each control face is active throughout the stroke length which it is tocontrol, and is given a predetermined contour designed to set up theparticular selected regimen of the stroke of the driven member. In thedrawings-Figs. l and 2-the arrangement (which is illustrative only) isassumed to provide a two-to-oneratio at the beginning of the stroke, thecontour at this point representing the position of the rollers H. at thebeginning of the stroke. The face Hi curves inwardly from thispoint-with face It curving outwardly from its corresponding point of theopposite extreme-to an intermediate point, after which the facecontinues parallel with the path of travel of the drive member. If alarger ratio is desired, a different curvature would be employed.Actually, each control face could be an line face with the necessaryinclination to set up tial relationship; the curved form is preferred,as offering a smooth operating stroke in which the differential can bedissipated somewhat prior to the end of the stroke.

As will .be seen, the two faces are so related that when the roller I2is in the position X- which is assumed to represent the lower extreme ofreciprocation of the driven memberthe roller is in contact with thecurved portion of face 14, and is just out of contact with the straightportion of face l5. The particular distance between the faces at thispoint will be properly selected, but, in practice, it would be such asto leave a slight space between the roller and face l5 when the rollercontacts face H3 in this position; for instance, if the roller be of twoinch diameter, the spacing of the faces at such point would beapproximately 12%;. In other words, the arrangement is such that at notime does the roller bridge the space between the faces, but in thepositions which represent the two ends of the stroke of the drivenmember, the spacing of the two faces approaches the diameter of thewheel dimension but is sufficiently larger as to assure definiteclearance between the roller and face IS in this position.

This spacing is designed to provide the delay period referred to. Duringthe downward travel of the drive member, roller l2 travels in contactwith face l5. When the lower extreme of drive member stroke is reached,the leverage carrier ends its downward movement-'but with the rollerstill in contact with face l5. As the drive member passes its nadirpoint and begins its upward stroke, it draws on lever II, but at suchtime the resistance of the driven member is present, and since roller i2is .out of contact with face M at the instant of change, the resistanceand power are eifie'ctive in opposite directions with the result thatthese forces will cause roller l2 to the desired speed difierenleaveface l5 and pass into contact with face M. The time required to makethis shift represents the delay period referred to.

The shift in position of roller 4?. takes place through the travel ofthe drive member, so that the latter will have advanced a slightdistance on its upward stroke at the time the roller contacts face i l;the distance is small-a few degrees of arcuate travel of the power crankpin-but the crank pin will have passed its dead center position andtherefore is exerting an upward pull with the pull active on theleverage carrier. Initially, the pull is active to shift roller 12 fromcontact with face 15 to its contact with face M, as before explained,the resistance of the driven member causing the link I2 to rock lever Hon pivot I la to draw the roller inward, until contact of the roller l2with face 14 causes the carrier to present the characteristics of alever of the second order which, when established, causes the pull ofthe drive member to be communicated to pin ill through the linkconnection l3.

However, due to the curvature of face upward travel of lever ence of theresistance changes the angularity change in angularity Hi, this ii androller l2in presof the driven memberof lever H and consequent of thelink connection 53, so that the distance traveled by the driven memberper unit of time is less than that of the drive member, the value of thedifferential being determined by the position of the roller on face 14.At the beginning of the stroke the ratio illustrated would approximate atwo-to-one ratio. As the roller advances, however, the changes inleverage angularity of lever and link gradually set up the conditionwhere the differential is completely dissipated, so that when the rollerl2 reaches the parallel position, the two members travel at equal speedsand distances during the remainder of the stroke, due to the constancyof the leverage positions during the latter portion of the stroke.

When the crank-pin reaches its zenith pointpresenting the upper extremeof reciprocation of the drive member-the driven member will also havereached its upper extreme, with the roller still in contact with faceit. However, when the drive member begins its return stroke afterpassing the zenith, the resistance of the driven member again becomeseffective in opposition to change on the part of the driven member, withthe result that the downward movement of the lever l I will be resistedby pin Iii, acting through link It, thus rocking lever H to carry rollerI2 into contact with face i5, thus setting up the latter as the controlface during the succeeding downward travel of the carriers, and duringwhich the initial two-to-one ratio becomes manifest and is followed bythe gradual dissipation of the differential as described in connectionwith face i l.

As is apparent, the length of the stroke of the driven member is lessthan that of the drive member, the difference in stroke length beingdetermined by the selected ratio and the length of the zone ofdissipation of the differential; during travel within this zone, thespeed of the driven member is less per unit of time than that of thedrive member, so that the distance travelled is less. However, this factis not detrimental, since it is obvious that the power source anddrive-member stroke will be arranged to provide the desired length ofdriven member stroke. In other words, the time length of the strokecycle of both members is the same, but the start would be present within direction which has been made by the drive.

Such resistance is present where the system in which the pumping elementis in pumping activity during both strokes. Because of this the presentinvention is especially applicable for service in this particular fieldof pumping activity. However, it is not limited to such field, since itis also applicable for use with single acting pumping systems. In thelatter, the load the upward stroke, so that during such stroke theconditions would not change. Since, however, the resistance due topumping action is absent during tihe downward stroke with asingle-acting pump, the weight of the driven member would remain presentas a factor tending to move the driven member downward, additional tothe drive member. This might lead to the assumption that this force,drawing on pin I0, would cause link l3 to draw lever II inward and causethe downward travel of the leverage carrier to be controlled by face l4.

However, the latter condition is actually not present. When the drivenmember begins its downward stroke from its upper extreme ofreciprocation, the pumping valve opens, and the area of this valve isalways less than the crosssectional area of the pumping cylinder, withthe result that there is developed a resistance value due to the effortto displace a larger fluid volume through a smaller port; where thedriven member is of a type in which the weight factor is insufficient toovercome this resistance, the structure will operate similarly to thedoubleacting pumping system regimen. Should the driven member be of atype which would so increase the weight factor as to overcome thisresistance value, the condition is met through theaddition of a springl6 between the drive and driven members, such spring opposing thetendency of the weight factor to draw the driven member downward at aspeed such as to draw the roller in from face I 5, the spring tending toact as a resistance opposed to the excess of the weight factor over theresistance value. If spring l6 be of the expansion type, its greatestresistance will be in the upper zone of the travel of the drive member;if the spring be of the compression type, the greatest resistance willbe in the lower zone of such travel. This is due to the fact that theangularity of link l3 changes as the roller I2 traverses the curvedportion of the control face, the angularity of the link to thehorizontal being greatest during travel of the roller over the portionof control face [4 extending parallel to the path of travel of the drivemember, this angularity decreasing within the curved portion of suchface; as a result, the distance between the attaching points of thespring on the two members will be least at the lower extreme ofreciprocation, and greatest at the upper end of the curved portion offace [4, since travel of the roller toward this point has the 7 effectof increasing the angularity of the link to the horizontal; theangularity of the link remains constant during travel of the roller overthe straight portion of the face l4 toward and to the upper extreme ofreciprocation. Similarly, the

reverse action'takes place during downward travel of the roller over thecurved portion of face IS- the angularity of link l3 to the horizontalbecomes static when the straight portion of this face is reached.

Should, however, the conditions arise that the weight factor overcomethe resistance during such downward travelwith a resultant indrawing ofroller ii! to contact face II, the operation is not fatally affected,since the inward movement of roller l2 will then bring the roller thelatter face, and present the conditions produced by the structure of thecompanion applicationcausing the approach to the lower extreme ofreciprocation of the driven member to be made under the conditions of adifferential of speed relative to the drive member. of the drive memberstroke, the roller will have The above explanation will sure of FigureFor instance, in Fig. 10, it is apparent that each stroke of the pistonis an active stroke-- move the piston in either direction, the pumpprovides a resistance active to resist a change in direction of thestroke, efiective in both extremes of reciprocation of the piston, thussetting up the conditions which cause shift of contactor i2 from onecontrol face to the other as explained above.

In Fig. 9 the showing is that of a single acting lift pump (shownconventionally) with the valves shown as of the pivoted or fiat type,one of which controls a port through the piston. During the up strokethe content above the piston is being discharged into the outletthepiston valve is closed-while the piston draws in fluid into the spacebelow the piston; during the down stroke the supply valve is closed asis the outlet valve, while the piston valve is open, so that,theoretically, the piston is simply travelling through the contentplaced below the piston during the previous stroke; theoretically, thisdisplacement of the piston would be under unloaded conditions, and thuswithout material resistance effect; but the difference in area betweenthe piston and the port therethrough actually provides, in practice, theresistance values desired in the upper extreme Where the piston changesfrom the up to the down strokein the lower extreme the normal loadedcondition of the pump provides the resistance eflfect, As a result, thecontactor I2 is shifted to the opposite control face in both of theextremes of reciprocation of the drive member and the unit carrier A.

Figures 3 to 8 present an illustrative form of structure of the unitassembly which may be employed in carrying out the invention. The actualstructure may have a number of different forms depending upon thespecific installation being provided, the structure disclosed presentinga simple arrangement which will indicate the underlying characteristicspresent, and is therefore more or less illustrative of such variousforms.

The control faces l are shown as the inner faces of side walls of acasing 20, the latter having end walls 28a and 20b arranged with alinedopenings to receive ways 2|, 2| which are spaced apart to receive andguide a carrier 22 which, in effect, is the portion of the drive memberA operating in the casing; the uppei end of the carrier has an operativeconnection with the power source through link L. Obviously, the casingmay be independent of faces l5, if desired; and, similarly, ways 2| maybe integral with the casing end-walls. The outer faces of ways 2| mayform the straight portions of control faces 14, in which case the curvedportion of such control face would lead from such way face and beconnected to the bottom wall of the casing; obviously, control face Itmay be provided by a face completely separate from a way 2|.

The carrier 22 is provided with an elongated recess 22a, shown asextending inward from its lower end, said recess being adapted toreceive a slidable element 23; the recess is of greater length than theelement, and the recess end is closed by a closure 22b; element 23 isdesigned to support pin It and form an extended structure which willensure travel of the pin in a true rectilinear path during the operationof the unit as presently described in detail. The carrier 22 is alsoprovided with a slot 220 on the forward and rear faces, these slotsextending into the recess; the slots 220 permit the movement of the pinl9 relative to the carrier in a longitudinal direction of the latter.While the carrier is shown as having a slidable mounting in the ways 2|,and the element 23 has a similar mounting in the carrier, it will bereadily understood that, to decrease friction, the carrier may haverolls mounted to contact the ways 2|, and the element may carry rollscontacting the walls of the recess, this being an obvious antifrictionarrangement which may be employed.

The levers may have any desired structural arrangement, the drawingsillustrating each of them to be of fabricated type through making eachlever in the form of a pair of arms 24 connected respectively to thefront and rear faces of the carrier by a pin Na and which have theirfree ends supporting roller l2 which is mounted between the arms. Eacharm has a link connection with pin lil, so that each link |3 thusbecomes a fabricated structure which has a connection with pin H] onboth the front and rear faces of the carrier, pin l0 having a lengthsufficient to receive the links from both sides of the unit outside ofthe carrier, suitable securing devices being employed; by thisarrangement the power applied to the pin from the drive member is madeeffective to ensure that no torsional effects are placed on the pinduring operation.

' fact that the two faces in the It is apparent that while the rollers|2 traverse the straight portions of control faces M and I5, the leversN do not change their angularity to the path of movement of the carrier;and since the links I3 are of constant length, the angularity of theselinks to the horizontal does not change, since the paths of travel ofthe pin Ill and the pivots on which the links are secured to arms 24 arethen parallel. However, as soon as the rollers pass on to the curvedportions of the control faces M or l5, the roller tracks the face withthe result that the travel of the pivot of the links on the arms variesfrom such parallel travel path, with the result that the angularity ofthe links l3 is varied, since the constant distance between the linkpivots and the location of the pin forces the pin and its supportingelement 23 to move in recess 20c and relative to the carrier, the lengthof such relative movement depending upon the length of travel of theroller l2 along the curved portion of the control face. For instance, inFig. 8 the roller is shown at an intermediate position; if the carrieris moved upward, the roller face contacts a portion of the control facecloser to the axis of reciprocation, and the angularity of the links tothe horizontal will increase, thus causing the pin Iii and itssupporting eieinent to travel downward in the recess and slots relativeto the carrier, although both elements may be actually travelling in thesame directionthe rate of advance of the pin is reduced relative to thatof the carrier. On the contrary, if the movement of the roller isdownward from the position of Fig. 8, the distance of the roller fromthe axis of reciprocation is increased, and the links i3 will have theirangles varied to the horizontal in a direction to cause the pin lilandits supporting element to move upward relative to the carrier, althoughboth may be moving downward.

As will be understood, the inclination of the links l3 will depend uponthe location of the outer pivots relative to the axis ofreciprocation-the inner pivot (the connection of link and pin H1) islocated in the axis of reciprocation, so that the distance of the outerpivot from such' axis will control the link inclination; with therelation of the outer pivot determined by the arm II, it is apparentthat as the control face contour changes the distance between the rollerand the axis of reciprocation, such change becomes effective to shiftthe position of the outer link pivot, as the distance is increased ordecreased. This distance remains constant on the portions of the controlfaces which extend parallel with the axis of reciprocation-thusretaining the angularity of the links constant in this zone; when,however, the roller traverses the curved portions of these controlfaces, the angularity of the links change, thus causing pin l0 and itssupporting element to be advanced or retarded with respect to thecarrier, but without breaking the drive relationship between the carrierand pin, even though there is a momentary break in the support for theroller at the instant of reversal of the stroke of reciprocationprovided by the shift of the roller from one control face to the other;during the break in support, the connection between carrier and pinremains constant, but becomes inactive as a driving medium for the pinduring the period when the roller is out of contact with either face-amomentary period, due to the extremes of reciprocation are spaced adistance only slightly greater than the roll diameter.

As pointed out above, the shift of the roller from one face to the otheris provided by the fact that the direction of travel of the drive memberis suddenly reversed by the movement of the power source through thezenith or nadir points. At such time of reversal of the stroke of thedrive member, the same reversal will take place in the pin I la of armII, but to provide a simultaneous reversal of the stroke of pin II), theroller I 2 would need to provide a positive resistance in order to forcethe pin to move; at this instant-the moment of change of drive memberstroke to its new direction-the control face active during the approachof the driven member becomes inactive, provided there is any resistancevalue to change in stroke direction by the driven member. With adouble-acting pumping system, such driven member resistance is presenton both strokes-in single-acting pumping systems, the smaller valveopening provides a resistance as explained above. Hence, at the instantof change of the stroke of the drive member, the driven memberresistance becomes active in opposition to the change with the resultthat the link becomes active on the arm to force the roller away fromits previous control face, this movement continuing until the rollercontacts the other control face and thus sets up a resistance againstfurther yield of arm II; when this occurs, the drive efiect of the drivemember again becomes active on the pin l0, and the driven member, withthe newlyactive control face determining the position of the roller asthe drive member continues through the stroke.

spring 16 in order to afford an additional resistance to the drivenmember during the downward stroke of such driven member, this being theidling stroke with such systems. The spring may be of the tension or thecompression type, as before indicated, and need not present a largepower value, since it is used only to augment the normal resistanceprovided by the smaller valve opening. The spring operatively connectsthe drive and driven members, if of tension type, or is located betweenthe members if of compression type. For purposes of illustration thespring effect is illustrated in dotted lines in Fig. 3, by a pair ofsprings connected to opposite side portions of one or both arms of thedriven member and leading to suitable points on the carrier; theconnection may be of any suitable formas by hooks carried by the ends ofthe springs. With double-acting pumping systems such spring structure isunnecessary.

The driven member B is illustrated only by its upper end portion, thisbein represented by the arms 25 which, as indicated in Fig. 4, extenddownward from pivot Ii]; the lower ends of the arm will be secured tothe upper end of the pump rod which therefore completes the drivenmember. This provides a simple arrangement of unit assembly and assuresthe essential strength and rigidity in service.

The fabricated form of structure enables the unit to be readilyconstructed with the dimensions arranged to meet; the individualinstallation. If desired, suitable anti-friction rollers or otherstructures may be utilized, and, if desired,

the unit casing may be arranged to contain lu- 75 bricant, in which casethe movements of the parts would be in an oil bath.

As will be understood, the distance of the straight portion of controlface l5 from the axis of reciprocation is never greater than can bebridged by the linkage without bringing link I 3 actually to thehorizontal. In other words, the length of such links is such that whenthe levers I I are swung outward to the greatest distance permitted bycontrol face N3, the links l3 will still remain angular to thehorizontalthe links never reach a position where they could shift to theopposite inclination; while the angularity of the links to thehorizontal may vary, as pointed out, the variations take place always onthe same side of the horizontal.

As will be apparent, the length of the dwell period of the driven memberis controlled entirely by the spacing of the two control faces at theextremes of reciprocation; a slight increase causes carrier 22 to beginmovement in the reverse direction while pin l0 remains stationary due tothe resistance of the driven member; as a result, opposing pressures areplaced on the link pivot to the arms in a direction opposing that whichwould be required to apply power from the carrier to pin In. As long asthe arms can, swing under such action, the power effect of the carrieris inactive on the pin; the inactivity ends when roller l2 contacts thecontrol face toward which the arms are swinging; when contact is had,the leverage becomes active to transmit power to the pin.

During this period inactivity of transmitting power to the pin I ll, thecarrier continues its movement in the new stroke, due to the 'fact thatthe power source continues its travel past the zenith and nadir points.Hence, the number the roller when shifting from face to face-the inorder to provide the dwell action that is deon the driven member.

While I have shown and described the invention as used in connectionwith pumping systems, it will be readily understood that the inventionis not limited to this particular field, but is applicable for usewherever the conditions of a the possibilities of detrimental kineticenergy developments tend to reduce the possible operating speeds. Thepossibility of using a drive member of short length and light weight, aswell as the ability to mount such member in such manner as to ensuretravel only in a reciprocatory path and with a minimum of resistanceinits own operation-thus practically eliminating the development ofdetrimental kinetic energy within itself, and therefore sensitivelyresponsive to the control of a rotative power source-makes it possibleto utilize the invention and obtain higher speeds of operation where thedriven member is such as would develop detrimental kinetic energy athigher speeds in the absence of the invention. By interposing the delayperiod between the two periods of inertia of motion, assurance is hadthat the detrimental kinetic energy will be dissipated even at thehigher speeds of operation, and thus increase the capacity of themechanism so equipped with the invention.

The above disclosure the use of control faces 14 and 15 designed topresent like action with both strokes of the driven member; the valuesof the differential speed relationships between the drive and drivenmembers, and the range of the zone of such differential status, may varyto meet the conditions of individual installations, but thecontemplation is that these values are similar in both strokes of thedriven member, this being the preferred arrangement.

However, installation conditions may be such as to make it advisable toprovide diiferent values to the two faces, and such variation is alsocontemplated within the present invention. For instance, where the powersource moves in a circular orbit and the driven member is driventhereby, the arrangement of the latter is generally with the powersource connection located at the opposite end of the driven member tothat of the pumping piston; under such conditions, one stroke of thedriven member is under the conditions of pull and the opposite strokeunder the conditions of push. With a driven member of considerable orgreat length, it would be difficult to set up an assemblage in which themember is supported against b ending or buckling throughout its length,if the operating conditions were such as to provide opposing pressuressuch as to cause bending or buckling intermediate the ends of the drivenmember-as when the resistance value of the piston as opposed to thespeed value of the power source are such that the driven end of thedriven member would materially overrun the speed of the piston permittedby the resistance.

The possibilities of such conditions are greatest at the mid-zone of thetravel of the crank pin between nadir and zenith positions, and thepresent invention contemplates meeting the possibilities by includingsuch mid-zone within the range of the differential speed relationship;in such case the speed of the driven member does not reach the maximumvalue of the drive member, since the two members come into the oneto-onedrive relationship only when the crank pin has reached a point in itsorbit where the speed of the drive member is decreasing. Such conditionsare within the above contemplation.

However, it is obvious that the undesired pressure conditions couldoccur only during the push stroke of the driven memben-as where thepumping system is of the double-acting type-since bending or bucklingwould not occur when the member is being pulled; hence, the operatingconditions between the two strokes present different conditions undersuch circumstances. It may be desirable, for operating conditions thatduring the pull stroke the range of the differential zone may be greateror less than during the push stroke. For instance, with, a

generally contemplates driven member in which the weight factor isreduced, the possibilities of bending or buckling would be increasedduring the down stroke while it would be possible to set up theone-to-one drive relation between the members at an earlier periodduring the pull stroke-in such case the differential speed value andrange witlnn which it is made manifest can be made diz'ferent as betweenthe control faces-face it being arranged to provide a range such as toavoid the development of material bending or buckling, while the contourof face i4 would be arranged to meet the more favorable conditionsprovided by the pull stroke. Or, .on the other hand, the driven membermay havea structure and weight factor which is least likely to bender.buckle, but which could provide a material weight factor active inopposition to the power; in such case the contour of face i4 could bearranged to present the greater values as to differential in speed and-range, and thus tend to set up an increased, power factor activeduringthe pull stroke.

These present but a few of the-possibilities of installation problems,and are being referred to specifically to illustrate the extremeflexibility of the invention through the ability to control the contoursof the control faces I l and it to meet individual problemcharacteristics of a particular installation.

The specific structure shown is more or less illustrative, being asimple and compact arrangement which is capable of carrying out theunderlying fundamentals of the invention. The fabricated form of thelinks and levers is shown be in the form of stampings. However, it' isapparent that the character of the installation will control thephysical structure to be employed, as well as the form and dimensions ofthe various elements employed, similarly,.the individual preferences ofthe engineer as to these characteristics can lead to preferredmodifications. I therefore desire to be understood as reserving theright to make any and all such variations and modifications therein asmay be needed to meet these conditions, insofar as the changes andmodifications may fall within the spirit and scope of the invention asexpressed. in the accompanying claims, when broadly construed.

I claim:

L In motion transmitting mechanism, a reciprocatory drive member, apower source operative to provide and control the timing and length ofreciprocation of such drive member, a rec'iprocatory driven member ingeneral alinement with the drive member, and a leverage unit operativelyconnecting the reciprocatory drive and driven members, said unit havinga direct drive connection with such drive member to thereby bodilyreciprocate the unit in synchronism with the drive member and havingdirect connection with the driven member to thereby drive the latter,said unit including means operative to vary the drive relation betweenthe members by varying the leverage angularity of lever elements tothereby control the movement of the driven member, said drive and drivenmembers and said unit being co-related in operation to provide thefollowing sequence of reactions by the driven member to thereciprocation movements of the drive member: during approach of thedrive member to its. extremes of reciprocation the driven memberapproach to its extreme of reciprocation is concurrent therewith and ata definite speed ratio. thereto; during the succeeding change indirection of stroke of the drive member, the beginning of the stroke ofthe driven member is delayed with respect to the beginning varying thespeed ratio between the drive and driven members until the ratio becomesthat of the approach period.

2. Mechanism as in claim 1 characterized in that the speed ratio betweenthe drive and driven members during the approach period is substantiallyone-to-one, and with the speed of the driven member stroke beginning asless than that of the drive member in a ratio of at least two-toone.

3. Mechanism as in claim 1 characterized in that the power source anddrive member are operatively connected to provide the relationship ofconverting rotary motion of the power source into reciprocatory motionof the drive member, with the extremes of reciprocation of the drivemember provided by the zenith and nadir points of the power sourcemovement, the delay period of the driven member beginning at such zenithand nadir points and continuing during the ad-- vancing travel of thepower source from such points for a few degrees of angular travel of thesource.

4. In motion transmitting mechanism, a reciprocatory drive member, apower source operative to provide and control the timing and length ofreciprocation of such drive member, a reciprocatory driven member ingeneral alignment with the drive member, and a leverage unit preventconcurrent engagement of the contactor with both faces during a strokeof the drive member, said contactor being shiftable from engagement withone control face to engagement with the other control face within theend zone of reciprocation of the drive member.

5. Mechanism as in claim 4 characterized in that the contour of each 6.Mechanism as in claim 4 characterized in that the contour of eachcontrol face is such as to provide a substantially one-to-one speedrelationship between the drive and driven members during the approach ofthe members to their extremes of reciprocation, and to provide adifferential speed the opposite direction of reciprocation.

8. Mechanism as in claim 4 characterized in that a control face isactive with the contactor substantially throughout the length of astroke 9. Mechanism as in claim 4 characterized in that the power sourceis of the rotating type and operatively connected with the drive memberto 10. Mechanism as in claim 4 characterized in that the driven 12.Mechanism as in claim 4 characterized in that the lever is of fabricatedspaced-ply type with the roller located between plies, the link is ofsimilar type with the link plies overlying the lever plies, and that theadjacent end of the driven member is of similar type, having its pliesoverlying the link plies at the point of connection of links and drivenmember.

13. Mechanism as in claim 4 characterized in that the contour of eachcontrol face is such as to provide a definite speed relationship betweenthe drive and driven members during the approach of the members to theirextremes of reciprocation, and a predetermined percentage diiferentialspeed relationship between the members at the beginning of the stroke ofthe driven member, the contours of the opposed control faces presentinglike values throughout the length of the faces.

14. Mechanism as in claim 4, characterized in that the contour of eachcontrol face is such as to provide a definite speed relationship betweenthe drive and driven members during the approach of the members to theirextremes of reciprocation, and a predetermined percentage differentialspeed relationship between the members at the beginning of the stroke ofthe driven member, the contour of one of the opposed control facespresenting a different value of speed relationships and/or range of suchrelationship from that presented by the opposed control face.

BRYAN BRASSELL.

